Viscosity as an Experimental Tool in Studying the Mechanism of Stereoselective and Product-Selective Chemical Transformations through Frictional Impositions

2003 ◽  
Vol 36 (8) ◽  
pp. 571-579 ◽  
Author(s):  
Waldemar Adam ◽  
Alexei V. Trofimov
Keyword(s):  
Chemical Transformations ◽  
Experimental Tool ◽  
Selective Chemical

scholarly journals Enamine/Transition Metal Combined Catalysis: Catalytic Transformations Involving Organometallic Electrophilic Intermediates

2019 ◽  
Vol 377 (6) ◽  
Author(s):  
Samson Afewerki ◽  
Armando Córdova
Keyword(s):  
Transition Metal ◽  
Metal Complex ◽  
Carbonyl Compounds ◽  
Transition Metal Catalysis ◽  
Chemical Transformations ◽  
Considerable Effort ◽  
Metal Catalysis ◽  
First Report ◽  
Wide Range ◽  
Selective Chemical

AbstractThe concept of merging enamine activation catalysis with transition metal catalysis is an important strategy, which allows for selective chemical transformations not accessible without this combination. The amine catalyst activates the carbonyl compounds through the formation of a reactive nucleophilic enamine intermediate and, in parallel, the transition metal activates a wide range of functionalities such as allylic substrates through the formation of reactive electrophilic π-allyl-metal complex. Since the first report of this strategy in 2006, considerable effort has been devoted to the successful advancement of this technology. In this chapter, these findings are highlighted and discussed.

Stereochemistry of Dehydrogenation by D-Galactose Oxidase

1971 ◽  
Vol 49 (21) ◽  
pp. 3429-3437 ◽  
Author(s):  
A. Maradufu ◽  
G. M. Cree ◽  
A. S. Perlin
Keyword(s):  
Hydrogen Atom ◽  
Isotope Effect ◽  
Galactose Oxidase ◽  
Relative Impact ◽  
Chemical Transformations ◽  
Product Analysis ◽  
Deuterium Isotope Effect ◽  
Oxidation Rates ◽  
Selective Chemical ◽  
Sugar Derivatives

The stereochemistry of dehydrogenation of the primary carbinol group of D-galactose by D-galactose oxidase has been determined. Using D-galactose-6-d and methyl β-D-galactopyranoside-6-d, it has been established that the reaction involves removal of the pro-S 6-hydrogen atom. This conclusion is based on product analysis, and on the relative impact of the deuterium isotope effect on oxidation rates of substrates having different R:S deuteration patterns. The absolute configurations at C-6 of these substrates have been determined by selective chemical transformations to products of known configuration. The rotational conformation of the 6-carbinol group of D-galactose and its possible relationship to the specificity of the enzyme are discussed, as well as the stereochemistry of reductive deuteration of aldehydo sugar derivatives.

Biosynthetically-inspired oxidations of capillobenzopyranol

2017 ◽  
Vol 15 (22) ◽  
pp. 4811-4815 ◽  
Author(s):  
Henry P. Pepper ◽  
Hiu C. Lam ◽  
Jonathan H. George
Keyword(s):  
Marine Sponge ◽  
Chemical Transformations ◽  
Selective Chemical

The marine sponge meroterpenoid capillobenzopyranol has been converted into the co-isolated verrubenzospirolactone using simple and selective chemical transformations.

scholarly journals Exploration of new reaction tools for late-stage functionalization of complex chemicals

2019 ◽  
Vol 97 (2) ◽  
pp. 67-85 ◽  
Author(s):  
Alejandra Dominguez-Huerta ◽  
Xi-Jie Dai ◽  
Feng Zhou ◽  
Pierre Querard ◽  
Zihang Qiu ◽  
...  
Keyword(s):  
Environmental Impact ◽  
Late Stage ◽  
Chemical Transformations ◽  
Synthetic Route ◽  
Atom Economy ◽  
Complex Molecules ◽  
Mild Conditions ◽  
The Past ◽  
Renewable Feedstocks ◽  
Selective Chemical

Chemistry has always had as a target the conversion of molecules into valuable materials. Nevertheless, the aim of past synthesis has primarily focused on achieving a given transformation, regardless of the environmental impact of the synthetic route. Given the current global situation, the demand for sustainable alternatives has substantially increased. Our group focuses on developing selective chemical transformations that benefit from mild conditions, improved atom economy, and that can make use of renewable feedstocks as starting materials. This account summarizes our work over the past two decades specifically regarding the selective removal, conversion, and addition of functional groups that can, later on, be applied at a late stage for the modification of complex molecules.

Synthesis and Antimicrobial Activity of (Z)-2-(4-((5-((1-Benzylpiperidin-4-yl)methylene)- 2,4-dioxothiazolidin-3-yl)methyl)-1H-1,2,3-triazol-1-yl)-N-phenylacetamides

2021 ◽  
Vol 6 (4) ◽  
pp. 315-321
Author(s):  
Ashokbhai R. Rathod ◽  
Kapil Kumar Galachar ◽  
Chandan Kumar Pashavan ◽  
Sushil S. Korgaokar ◽  
Yogesh T. Naliapara
Keyword(s):  
Antimicrobial Activity ◽  
Click Chemistry ◽  
Analytical Techniques ◽  
Chemical Transformations ◽  
Biological Application ◽  
Selective Chemical

In current times, researchers adopted the click chemistry approach for the synthesis of various druglike molecules by using a few reliable, feasible, practical and selective chemical transformations via click formation. In present work, we focussed on the most triazole clubbed thiazolidine-2,4-dione derivatives as the most promising motifs for broad biological application. A total of fifteen (CF-4a-o) derivatives were synthesized and well characterized with various analytical techniques.

scholarly journals Origin and Control of Chemoselectivity in Cytochrome c-Catalyzed Carbene Transfer into Si–H and N–H bonds

2021 ◽  
Author(s):  
Marc Garcia-Borràs ◽  
S. B. Jennifer Kan ◽  
Russell D. Lewis ◽  
Allison Tang ◽  
Gonzalo Jiménez-Osés ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Bond Formation ◽  
Conformational Dynamics ◽  
Active Species ◽  
Chemical Transformations ◽  
Carbene Insertion ◽  
Biological World ◽  
Selective Chemical ◽  
And Control ◽  
Loop Conformation

<div><div><div><p>A cytochrome c heme protein was recently engineered to catalyze the formation of carbon–silicon bonds via carbene insertion into Si–H bonds, a reaction that was not previously known to be catalyzed by a protein. High chemoselectivity towards C–Si bond formation over competing C–N bond formation was achieved, although this trait was not screened for during directed evolution. Using computational and experimental tools, we now establish that activity and chemoselectivity are modulated by conformational dynamics of a protein loop that covers the substrate access to the iron-carbene active species. Mutagenesis of residues computationally predicted to control the loop conformation altered the protein’s chemoselectivity from preferred silylation to preferred amination of a substrate containing both N–H and Si–H functionalities. We demonstrate that information on protein structure and conformational dynamics, combined with knowledge of mechanism, leads to understanding of how non-natural and selective chemical transformations can be introduced into the biological world.</p></div></div></div>

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